This invention relates to a purification process of 4,4xe2x80x2-(9-fluorenylidene)diallylphenol.
4,4xe2x80x2-(9-Fluorenylidene)diallylphenol is useful as a raw material for polyesters and polyamides, and is known to permit construction of polymers, that develop optical, mechanical or various other functional characteristics, by introduction of its fluorene skeleton into polymer skeletons or by use of one or both of the allyl groups contained in its structure. As a process for the production of 4,4xe2x80x2-(9-fluorenylidene)diallylphenol, the process disclosed in JP 10-77338 A is known.
4,4xe2x80x2-(9-Fluorenylidene)diallylphenol is, therefore, expected to find utility as a raw material for functional polymers, and is desired to be supplied as a high-purity product. Due to its low crystallizability, however, it has heretofore been difficult to efficiently obtain 4,4xe2x80x2-(9-fluorenylidene)diallylphenol with sufficient purity.
An object of the present invention is, therefore, to provide an industrially advantageous process for the purification of 4,4xe2x80x2-(9-fluorenylidene)diallylphenol which is useful as a raw material for functional polymers.
The above-described object can be achieved by the present invention to be described hereinafter. Described specifically, the present invention provides a process for the purification of 4,4xe2x80x2-(9-fluorenylidene)diallylphenol. The purification process includes dissolving crude 4,4xe2x80x2-(9-fluorenylidene)diallylphenol with an inclusion-compound-forming solvent, which comprises an inclusion-compound-forming compound capable of forming an inclusion-compound with4,4xe2x80x2-(9-fluorenylidene)diallylphenol, to form the inclusion compound in a form of a solution, and then causing the inclusion compound to deposit.
In the present invention, 4,4xe2x80x2-(9-fluorenylidene)diallylphenol is represented by the following structural formula: 
According to the purification process of the present invention, 4,4xe2x80x2-(9-fluorenylidene)diallylphenol can be easily produced with high purity on an industrial scale although its purification and recovery have been difficult to date.
4,4xe2x80x2-(9-Fluorenylidene)diallylphenol purified as described above is useful, for example, as a raw material for polyesters and polyamides. By introduction of its fluorene skeleton into polymer skeletons, it is possible to obtain polymers which develop optical, mechanical or various other functional characteristics. Construction of polymers is also feasible by making use of one or both of the allyl groups in its structure. The present invention can, therefore, impart a still wider variety of functional characteristics to polymers.